You might be able to change variables. Instead of using nor(k), create a new variable that is equal to 1/nor(k). Call it nori(k). Then you need only ensure that nori(k) is greater than or equal to 1. Of course, if your objective function involves nor(k), you may be stuck.
Thanks. But how if I also have a constraint: [W(:,:,k), W(:,:,k)*h(:,k);
h(:,k)’*W(:,:,k), inv_pos(1-nor(k)] == hermitian_semidefinite(Nt+1); There are same problems when I try to express inv_pos(1-nor(k)) with 1/nor(k).